266 . GENERAL REMARKS 



in each variety of skull, and are not (see p. 235) distinctive of 

 either. A zone therefore bounded in front by a line drawn over 



the peculiarities of the veins of this portion of the cerebrum confirm us in holding. 

 One of the largest of the Pacchionian bodies is ordinarily found at the point where the 

 veins of the occipital lobe enter the superior longitudinal sinus, this point being upon 

 the line of the parie to-occipital fissure, and corresponding with what is usually the 

 most posteriorly placed of the foveae glandulares in the skull. Now the bodies known 

 as Pacchionian glands are growths which in their normal state are but -j^-^ mill, 

 in size, and which owe the increase in size which makes them prominent to the eye 

 and impresses them on the skull to venous congestion. The very constant presence 

 therefore of a largely hypertrophied Pacchionian body upon the embouchure of the 

 occipital veins is a significant fact as regards the retardation of their current (Wilks 

 and Moxon, in their 'Pathological Anatomy,' p. 208, compare these bodies to the 

 papillose outgrowths sometimes seen on the surface of the liver in cases of extreme 

 cardiac congestion). The amenability of the Pacchionian bodies to pathological change 

 is recognised by Bokitansky, * Pathological Anatomy,' English translation, 1850, 

 vol. iii. p. 329, or 2nd German edition, 1856, vol. ii. p. 407; by Jones and Sieveking, 

 in their 'Manual of Pathological Anatomy,' edited by Dr, J. Frank Payne, 1875, 

 p. 237 ; by Wilhelm Krause, in his 'Handbuch der menschlichen Anatomie,' 3rd ed., 

 1876, p. 460 ; and finally by Luschka, who was, as far as I know, the first to draw 

 attention to the fact that in their earlier stages and smaller size these bodies could 

 not be considered other than normal growths, in his 'Anatomie des Menschen,' 1865, 

 Bd. iii. Abtheilung ii. p. 240. 



The histological inferiority of the occipital lobe is well known, and though Mr. 

 Lockart Clarke may slightly overstate the case when he says (Maudsley, ' Physiology 

 of Mind,' 3rd edition, 1876, pp. 112 and 114) that 'all the nerve-cells are small,' both 

 Professor Turner ('Introduction to Human Anatomy,' part i. 1875, p. 283) and Pro- 

 fessor Henle ('Handbuch der syst. Anatomie,' iii. 2, p. 276) would allow that 'the 

 greater number of the cells of the occipital lobe are small and nearly uniform in size,' 

 and, what is of equal importance, that the superficial layer, which is everywhere poor 

 in cell-elements, is of greater width in the occipital than in any other region of the 

 brain. Meynert's words (' Strieker's Manual of Human and Comparative Histology,' 

 English translation by Power, vol. ii. p. 391, 1872) are eminently to the purpose : 'The 

 brain of monkeys, which is distinguished by excessive development of the occipital 

 lobes, contains this type of tissue (the pyramidal cells) in much greater abundance than 

 the human brain.' Dr. Herbert C. Major has given an instructive account of the 

 histology of the brain of the Chacma Baboon in the 'Journal of Mental Science,' 

 Jan. 1876, and refers therein to Meynert's memoir, I.e. 



As regards the connexion of the occipital lobes with mental functions, it is well 

 known that Neumann (cit. Cruveilhier, 'Anat. Descript.' ed. 1836, iv. p. 668 ; Longet, 

 'Systeme Nerveux,' i. 691, and 'Traite* de Physiologie,' 1869, iii. p. 444) was induced 

 from his examination of the brains of some fifty insane persons to hold that intelligence 

 had its seat in the occipital lobes ; and Cruveilhier is also quoted as speaking in the 

 same sense ('Anat. Descript.' I.e., and 2 de e"d., Paris, 1845, torn. iv. p. 346) from having 

 noticed that in senile dementia the occipital lobes are much more atrophied than the 

 frontal. These arguments, like so many in the same sphere, are amenable to the ob- 

 jection that the atrophy in question may be merely a concomitant change, correlated 

 in the way of mal-nutrition with some other really causative change, without being 

 itself the first term in the series of evils. It is however by no means necessary to 

 shelter ourselves behind this suggestion, for few if any mental alienists would be found 



